Biology of Reproduction, Vol 7, 247-253, Copyright © 1972 by Society for the Study of Reproduction

Nicotine Injection during Gestation: Impairment of Reproduction, Fetal Viability, and Development

¹ Department of Physiology-Anatomy, University of California, Berkeley, California 94720

In order to study the effects of nicotine on pregnancy and fetal development, rats were injected twice daily throughout gestation with graded doses of nicotine (1, 3, and 5 mg/kg) and studied in terms of reproductive capacity, weight gain and length of pregnancy as well as litter size and viability. Offspring of treated and untreated mothers were compared for birth weights. In one group of animals, the fetuses were delivered by cesarean section on a given day of gestation (Day 21) to assess developmental differences between these fetuses and those delivered spontaneously at term. A second series of experiments was designed to explore the effects of nicotine when administered for the first gestational week only. The higher doses of nicotine were found to prolong gestation; however, the birth weights of spontaneously delivered offspring of control and treated animals were comparable. At the higher doses, nicotine administration resulted in the production of fewer viable litters; maternal weight gain was less as the nicotine dose increased. Birth weight of offspring of nicotine-treated mothers delivered by cesarean section on Day 21 of gestation (1 day before normal spontaneous delivery) also showed a reduction as the nicotine dose increased and the percentage resorptions increased with increasing nicotine dose. A 3 mg/kg dose of nicotine injected for the first 8 days of gestation induced the same effects on mothers and fetuses as observed in the first series of animals treated chronically with 3 mg/kg nicotine. It is suggested (1) that nicotine has affected processes already operative during the first week of gestation; and (2) that these effects may be manifested in developmental disturbances at later growth stages.